A device for supplying cleaning solution to a cylinder washing apparatus of a printing press is described in the applicant's pending application Ser. No. 07/886,788, filed May 21, 1992, now abandoned. Compared with other known washing devices, it is characterized particularly in that the washing solution is conveyed in a circuit and thus reused. Ink residue and dye particles in the used washing liquid are concentrated in the distillation device and can be periodically disposed of without difficulty as industrial waste, and also the amounts of waste are small.
Experiments with the device as described in the applicant's above-mentioned application have shown that the distillate is not homogeneous; instead, water and solvent are produced in succession, depending on the conditions in the distillation device. The distillate is then returned to the actual washing apparatus, but, without further steps, this is troublesome because the distillate, as mentioned, is not a homogeneous mixture of washing solution.